1. Field of the Invention
The present invention relates to trigger sprayer valve devices and more particularly to valve systems and precompression valve systems for such trigger sprayer devices.
2. State of the Art
Trigger sprayers, trigger sprayer devices, and trigger actuated pump sprayers are well known and their use is commonplace in many households and businesses. Typically, a trigger sprayer includes a pump chamber whose volume is varied by movement of a piston within the pump chamber. The piston is typically biased by a spring and is attached to a trigger lever. Actuation of the trigger lever moves the piston within the pump chamber and compresses the spring; this is sometimes referred to as the pump stroke or pressure pump stroke. Release of the trigger lever releases the force on the spring and the spring pushes the piston back to a resting position; which is sometimes called the suction stroke or return stroke. A typical trigger sprayer also includes an inlet valve and an outlet valve. During the pump stroke, product in the pump chamber is pressurized and upon reaching a certain pressure the outlet valve is opened, allowing the product in the pump chamber to escape through the outlet valve. During the return stroke, the outlet valve is shut and the inlet valve is opened. The return of the piston caused by the spring force draws product through the inlet valve into the pump chamber. A typical trigger sprayer will also include a dip-tube for delivering product to the trigger sprayer inlet valve, and an orifice for dispersing the product exiting the outlet valve. The orifice may be attached to or included in a nozzle which is part of the trigger sprayer.
In some instances, it may be advantageous for a trigger sprayer to include a precompression system which is actuated during the pump stroke. A precompression system allows pressure in the trigger sprayer to build-up before product is released or sprayed from the trigger sprayer. The inclusion of a precompression system may provide beneficial results to the spray mechanics or may improve dispersion of a product from a trigger sprayer. Because of these and other advantages, perceived or real, trigger sprayers with precompression systems are in demand.
Examples of trigger sprayers and trigger sprayer systems which include precompression systems are described and illustrated in the following United States patents and patent applications which are incorporated herein by reference in their entireties: U.S. Pat. No. 5,522,547; U.S. Pat. No. 6,131,820; and U.S. Patent Application Publication 2008/0149671.
Trigger sprayer systems employing plastic parts, non-metal parts, or a reduced number of parts are also desired. For example, PCT Patent Application PCT/US10/031970 describes such systems and is incorporated herein in its entirety by reference.
Thus, it may be desirable to develop a simple valve system, such as a precompression valve system, for trigger sprayers.